MySQL的：獲取兩行作爲一個

Question

用戶表：

id | win | lose 
0 | 1 | 2 
1 | 2 | 8 

遊戲表：

id | user1 | user2 | data 
0 | 0  | 1  | 'some text' 

的DB是一個簡單的多人遊戲。我需要一個查詢來獲得用戶2，數據，和雙贏的數據爲用戶。這在MySQL中可能嗎？任何幫助將不勝感激。

Answer 1

你必須JOIN表users兩次這樣的：

SELECT 
    u1.win AS win1, 
    u1.lose AS lose1, 
    u2.win AS win2, 
    u2.lose AS lose2, 
    ... 
FROM games g 
INNER JOIN users u1 ON g.user1 = u1.id 
INNER JOIN users u2 ON g.user2 = u2.id 

Answer 2

你可以加入users表兩次：

SELECT 
    games.user2 AS user2_id 
    games.data AS games_data 
    user1.win AS user1_win, 
    user1.lose AS user1_lose, 
    user2.win AS user2_win, 
    user2.lose AS user2_lose 
FROM games 
JOIN users AS user1 ON user1.id = games.user1 
JOIN users AS user2 ON user2.id = games.user2 
WHERE games.id = ...